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+clc;
+// (a).Restoring to initial state by throttling process
+T1=303; //Temperature of air at state 1 in kelvin
+p1=1;  //Pressure of air at state 1 in bar
+p2=5; //Pressure of air at state 2 in bar
+p3=1;//Pressure of air at state 3 in bar
+T3=303; //Temperature of air at state 3 in kelvin
+Cpo=1.0035; // Specific heat at constant pressure in kJ/kg K
+R=0.287; // characteristic gas constant of air in kJ/kg K
+k=1.4; // Index of reversible adiabatic compression
+T2=T1*(p2/p1)^((k-1)/k); // Temperature after reversible adiabatic compression
+w12=Cpo*(T2-T1); // Work of reversible adiabatic compression
+s21=0; // Entropy change of air
+s32=-R*log (p3/p2); // Entropy change 
+s31=s32; // Net entropy change of air
+d_Ssurr=0; // Entropy change of surroundings because There is no heat transfer
+d_Suniv=s31+d_Ssurr; // Net Entropy change of universe
+disp ("kJ/kg K",d_Suniv,"Net Entropy change of universe = ","kJ/kg",w12,"Work of reversible adiabatic compression = ","(a).Restoring to initial state by throttling process");
+// (b).Restoring to initial state by by completing cycle
+T0=298; // Temperature of surroundings in kelvin
+d_Ssystem=0; // Entropy change of systrem is zero because it is cyclic process
+q31=Cpo*(T2-T3); // Heat rejected to the surroundings
+d_Ssurr=q31/T0; //  Entropy change of surroundings
+d_Suniv=d_Ssystem+d_Ssurr; // Increase in entropy of the universe
+disp ("kJ/kg K",d_Suniv,"Net Entropy change of universe = ","(b).Restoring to initial state by by completing cycle");